The present invention relates to negative impedance networks which have numerous application in the electronics art. Oscillators rely on the establishment of an effective negative resistance in conjunction with a resonant or tank circuit in order to achieve sustained oscillation. Negative resistance is also utilized in regenerative or super-regenerative amplifier design to achieve high gain. So-called Q-multipliers utilize negative resistance to adjust the Q of resonant circuits in narrow bandwidth filter designs. Other applications of negative impedance or resistance networks will readily occur to those skilled in the electronics art.
The typical design approach to establishing a negative impedance characteristic is to provide a two terminal network including an electronic voltage amplifier with positive or regenerative feedback fashioned such that the impedance, typically resistive impedance, presented across the network terminals has a negative characteristic. The use of voltage amplifiers renders this approach to establishing a negative impedance relatively complex in design and thus rather expensive to implement.
It is accordingly an object of the present invention to provide an improved negative impedance network.
An additional object of the present invention is to provide a negative impedance network of the above character which is highly stable in operation and insensitive to the dynamic characteristics of the active components incorporated therein.
A further object is to provide a negative resistance network of the above character which is highly suitable for monolithic integrated circuit implementation and thus is highly reproducible.
Still another object of the present invention is to provide a negative impedance network of the above character which is simple in construction and inexpensive to manufacture.
Other objects of the invention will in part be obvious and in part appear hereinafter.